When I started writing about sports science two decades ago, fueling advice for endurance athletes was simple. The goal was to take in roughly 60 grams of carbohydrate per hour, in order to preserve the limited supply of carbohydrate stored in your muscles and liver. More would theoretically be better, but studies had found that it simply wasn’t possible to absorb more than that from the stomach into the intestine.
The science has evolved since then, mainly with the realization that mixing different types of carbohydrate (like glucose and fructose) in specific ratios enables higher absorption rates. Current recommendations top out at 90 grams per hour, but recent studies have suggested that it’s possible to take in 120 grams per hour—and top athletes in cycling, ultra running, and other sports are reportedly going even higher than that.
In contrast to all this, a new study gave its subjects just 10 grams of carbohydrate per hour, and argues that this is all you need. This is a surprising and contrarian take, and I’m not suggesting you should swallow it whole. But it’s a good opportunity to…
